Parasympathetic Irenergic Receptor Agonist Research Paper

14. CHOLINERGIC AGONISTS AND CHOLINESTERASE INHIBITORS
CHOLINERGIC AGONISTS
Overview
“muscarinic receptor agonists” cholinergic agonists are drugs that act on acetylcholine receptors, thus causing excitation of the parasympathetic autonomic nervous system there are 2 types of acetylcholine receptors 1) NICOTINIC RECEPTORS - are receptor-mediated ion channels - 3 types RECEPTOR TYPE MUSCLE TYPE GANGLION TYPE LOCATION - neuromuscular junction - sympathetic autonomic ganglia - parasympathetic autonomic ganglia - CNS

CNS TYPE

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agonists of nicotinic receptors are discussed later (“depolarizing neuromuscular blocking agents”, see 16)

2) MUSCARINIC RECEPTORS - are g-protein coupled receptors
catecholamines are neurotransmitters that work on adrenergic receptors, thus causing excitation of the sympathetic autonomic nervous system activation of adrenergic receptors usually elicits effects opposite to those of parasympathetic muscarinic receptor activation (see 14) there are 2 types of adrenergic receptors 1) ALPHA RECEPTORS - 2 types RECEPTOR TYPE ALPHA-1 EFFECT - increased blood pressure (due to vasoconstriction) - midriasis (due to contraction of the radial fibers of the pupilary sphincter) - loss of accommodation (due to contraction of the radial fibers of the ciliary muscle) - decreased GI tract emptying (due to decreased peristalsis) - decreased urinary bladder emptying (due to contraction of the urinary bladder sphincter) - ejaculation (due to contraction of the seminal tract) - cardiac- and prostate hypertrophy (due to increased smooth muscle proliferation) - hyperglycemia (due to increased glycogenolysis in the liver) ALPHA-2 - decreased blood pressure (due to inhibition of the sympathetic vasomotor center in the brain stem and of the sympathetic- and parasympathetic ganglia, and following vasodilation) - decreased GI tract emptying - thrombosis (due to increased platelet aggregation) - hyperglycemia (due to decreased insulin secretion by the